package utils;

/**
 * Created by liyuhang on 2019-10-18.
 */

import com.alibaba.fastjson.JSON;
import com.ssfeng.youxia.zk.Constants;
import org.apache.commons.lang.StringEscapeUtils;

import java.util.*;

/**
 * 敏感词过滤
 */
public class SensitivewordFilter {
    private final Map sensitiveWordMap = new HashMap();

    public static int minMatchTYpe = 1;      //最小匹配规则

    /**
     * 构造函数，初始化敏感词库
     */
    private SensitivewordFilter(){
        this.addSensitiveWordToHashMap();
    }

    /**
     * 判断文字是否包含敏感字符
     * @param matchType  匹配规则&nbsp;1：最小匹配规则，2：最大匹配规则
     */
    public boolean isContaintSensitiveWord(String txt,int matchType){
        boolean flag = false;
        for(int i = 0 ; i < txt.length() ; i++){
            int matchFlag = this.checkSensitiveWord(txt, i, matchType); //判断是否包含敏感字符
            if(matchFlag > 0){    //大于0存在，返回true
                flag = true;
            }
        }
        return flag;
    }

    /***
     *
     * @param txt
     * @return
     */
    public boolean isContaintSensitiveWord(String txt){
        return this.isContaintSensitiveWord(txt, 2);
    }

    /**
     * 获取文字中的敏感词
     * @param matchType 匹配规则&nbsp;1：最小匹配规则，2：最大匹配规则
     */
    public Set<String> getSensitiveWord(String txt , int matchType){
        Set<String> sensitiveWordList = new HashSet<String>();
        for(int i = 0 ; i < txt.length() ; i++){
            int length = checkSensitiveWord(txt, i, matchType);    //判断是否包含敏感字符
            if(length > 0){    //存在,加入list中
                sensitiveWordList.add(txt.substring(i, i+length));
                i = i + length - 1;    //减1的原因，是因为for会自增
            }
        }

        return sensitiveWordList;
    }



    /**
     * 检查文字中是否包含敏感字符，检查规则如下：<br>
     */
    @SuppressWarnings({ "rawtypes"})
    public int checkSensitiveWord(String txt, int beginIndex, int matchType){
        boolean  flag = false;    //敏感词结束标识位：用于敏感词只有1位的情况
        int matchFlag = 0;     //匹配标识数默认为0
        char word = 0;
        Map nowMap = sensitiveWordMap;
        for(int i = beginIndex; i < txt.length() ; i++){
            word = txt.charAt(i);
            nowMap = (Map) nowMap.get(word);     //获取指定key
            if(nowMap != null){     //存在，则判断是否为最后一个
                matchFlag++;     //找到相应key，匹配标识+1
                if("1".equals(nowMap.get("isEnd"))){       //如果为最后一个匹配规则,结束循环，返回匹配标识数
                    flag = true;       //结束标志位为true
                    if(SensitivewordFilter.minMatchTYpe == matchType){    //最小规则，直接返回,最大规则还需继续查找
                        break;
                    }
                }
            }
            else{     //不存在，直接返回
                break;
            }
        }
        if(matchFlag < 2 || !flag){        //长度必须大于等于1，为词
            matchFlag = 0;
        }
        return matchFlag;
    }

    private static class SensitivewordFilterHolder {
        private static final SensitivewordFilter INSTANCE = new SensitivewordFilter();
    }

    public static final SensitivewordFilter getInstance() {
        return SensitivewordFilterHolder.INSTANCE;
    }

    public void addSensitiveWordToHashMap() {

        String words = Constants.SENSITIVE_WORD;
        words = StringEscapeUtils.unescapeHtml(words);
        String[] wordsArr = words.split("\\|");
        Set<String> keyWordSet = new HashSet<>(Arrays.asList(wordsArr));
        sensitiveWordMap.clear();

        String key = null;
        Map nowMap = null;
        Map<String, String> newWorMap = null;
        //迭代keyWordSet
        Iterator<String> iterator = keyWordSet.iterator();
        while(iterator.hasNext()){
            key = iterator.next();    //关键字
            nowMap = sensitiveWordMap;
            for(int i = 0 ; i < key.length() ; i++){
                char keyChar = key.charAt(i);       //转换成char型
                Object wordMap = nowMap.get(keyChar);       //获取

                if(wordMap != null){        //如果存在该key，直接赋值
                    nowMap = (Map) wordMap;
                }
                else{     //不存在则，则构建一个map，同时将isEnd设置为0，因为他不是最后一个
                    newWorMap = new HashMap<String,String>();
                    newWorMap.put("isEnd", "0");     //不是最后一个
                    nowMap.put(keyChar, newWorMap);
                    nowMap = newWorMap;
                }

                if(i == key.length() - 1){
                    nowMap.put("isEnd", "1");    //最后一个
                }
            }
        }
    }

    public static void main(String[] args) {
        SensitivewordFilter sensitivewordFilter = SensitivewordFilter.getInstance();
        Set<String> set = sensitivewordFilter.getSensitiveWord("巨屌", 1);
        System.out.println(JSON.toJSONString(set));
    }

}